configure_nexus

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden. It usefully discloses the auth requirement ("Requires API key") and the downstream consequence of skipping the call, but for a mutation tool it never says whether this replaces the entire nexus configuration or merges with existing states, nor whether omitted states are cleared.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, each earning its place: purpose, prerequisite, auth requirement. The primary purpose is front-loaded with no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter mutation tool with no annotations and no output schema, the description covers purpose, prerequisite, and auth. The one notable omission is the replace-vs-merge semantics of the nexus object, which matters for a configuration mutation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%: the nested nexus object, hasNexus flag, reason string, and example format are all documented in the schema. The description adds no syntax or format detail beyond that, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (configure) and resource (US state economic nexus), which is clearly distinct from the sibling tools (track_payment, calculate_tax, get_rates). It stops short of explicitly naming or contrasting a sibling, so it lands at 4 rather than 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

"Sellers must configure nexus to get non-zero tax results" gives a concrete when-to-use condition and prerequisite, which is exactly the context an agent needs before calling calculate_tax. It offers no when-not-to-use guidance or alternatives, keeping it at 4.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.